Gaseous electric discharge device



1934- M. PIRANI ET AL GASEOUS ELECTRIC DTSCHARGE DEVICE Filed Feb. 9, l95l INVENTORS ATTORNEY Patented Wee. 18, light 'tric discharge devices generally and more particularly the invention relates to such devices in which electron emitting bodies, heated to a red 5 heat, or to incandescence by the operating current of the device, are used as the electrodes of the device.

electrode chambers 'of such devices with a light impervious covering, utilizing only the light emitted by the positive discharge column of the device. available for the arts generally and particularly for use in signs a part of the light emitted by the gaseous electric discharge devices.

ering having a window in the vicinity of the electrodes is utilized to permit the passage of part of the light emitted by said electrodes. The window may be of any suitable shape though we prefer one of round shape so that it forms a brilliant point light source in contrast to the linear shaped light source of thepositive column, this being desirable to attract the attention of v an observer as for example in the use of such electric discharge \device to designate an exclamation point in sign structures. In this latter case the electric discharge device" is mounted vertically, the top electrode chamber being totally covered and the covering of the bottom-electrode chamber havinga round window in the vicinity of the heated electrode.

tion is shown in elevation, part of the electrode chambers being cut away to show the structure thereof.

charge device comprises a tube 1 filled with a luminous gas, such as neon, helium, argon, alone or in combination with mercury, surrounding the positive column discharge path, electrode chambers 2 being located at the ends of said tube 1. Electron emitting electrodes 3 aresealed into said chambers 2, said electrodes 3 being heated to an electron emitting temperature for the start of the electric discharge device and being maintained at a glow or an incandescent temperature by the operating current during the operation of said device. chamber is provided with a covering 4 extending i merger GASIEQNUS lElLlEDlllltllQ DISCHARGE DEVIMJE Marcello lPirani, Berlin-Wilmersdorf, and ltllans lEwest, Eerlin, Germany, assignors to General Electric @ompany, a corporation or New York amputee-m February a, 1931, Serial No. trestle lln Germany February. 318, 193d ll (Claim. ((011. 1176-441) The present invention relates to gaseous elecsulation material, or a Hitherto it has been the practice to provide the round shape.

the opening 6 serves as The object of this invention is to make In accordance with this object an opaque covboth sources.

useful in sign work.

those skilled in the art trodes and the halo surr In the drawing an embodiment of the inven- 'What We Claim as 11 Referring to the drawing the electric disopaque, the margin of adjacent the opaque en circular window being i The upper electrode longitudinal axis ofsai to the tubepart '1 surrounding the positive col-- umn, said coating being of opaque material and being, for example, a metal cap, or a cap of incoating of lacquer. The

lower electrode chamber also has an opaque covering 5, said covering 5 having an opening 6 in the region of the glowing electrode 3, said opening 6 having a suitable cross, square, or The glowing electrode 3, visible through the opening 6, has a brilliant halo and a window to permit the passage of the light emitted by the glowing electrode 3 and its accompanying halo. phenomena that the color of this bright light emitted by the electrode and its halo is somewhat different than the color of the positive column, is of no practical importance as the observer gets the same light impression from When the light tube described herein and illustrated in the drawingis mounted vertically it forms an exclamation point and is The It will, of course, be understood that various substitutions, modifications and changes in the forms and detailsof the device may be made by without departure from the broad spirit and scope of the invention, for example, various other ,tubes and electrode chambers may be provided with similar glowing electrodes, the electrode chambers being provided with a suitably shaped window to permit the passage of the light emitted by said elecounding them. ew and desire to secure by Letters Patent of the United Statesis:

In a sign, an electric discharge device comprising a linear container, electrodes sealed therein, a gaseous atmosphere therein, an electrode chamber at each end thereof, said container having a linear shape, said electrode chambers and one end of said linear container adjacent one of said chambers being the opaque end of said container being notched, the electrode chamber d of said container having a circular light pervious window in the vicinity of the electrode mounted in said chamber, the point of said notch and the center of said n the same plane as the (1 container. MARCELLO PIRANI. HANS EWES'I; 

